TEMPE, ARIZONA--The long-legged, relatively big-brained hominid called Homo erectus has long been considered the Moses of the human family--the species that led the first exodus out of Africa more than 1.5 million years ago. But that view was challenged recently by three even older skulls found in Georgia. Now a small Kenyan skull ties the Georgian fossils more closely to H. erectus. It may help return H. erectus to its venerable status as the first intercontinental traveler.
Last year, a team working in Dmanisi, Georgia, uncovered three small, 1.75-million-year-old skulls that are older and more primitive than any H. erectus in Africa. They raised the startling possibility that an earlier, small-brained species left Africa first (Science, 5 July 2002, p. 26 ). Researchers are still debating whether the Georgian skulls are members of H. erectus or a more primitive species.
The 1.55-million-year-old skull was introduced here at a late April meeting of the American Association of Physical Anthropologists and identified as the smallest H. erectus known. It bears a surprising resemblance to the smallest skull from Dmanisi, according to paleontologist Meave Leakey, whose team from the National Museums of Kenya dug up the African fossil in 2000. As team member Fred Spoor of University College London, U.K., noted in his talk, both have classic H. erectus features, including a characteristically angled ear bone and a raised keel on the top. Until now, such a keel has been common in H. erectus specimens from Asia, but not African skulls. The Kenyan skull thus ties the Georgian fossil more closely to H. erectus in Africa.
The new find "shows the incredible variation in size within H. erectus," says Spoor. It and the Dmanisi skull might be so small because both were from young adults or teenagers, or from females, says Susan Antón of Rutgers University in New Brunswick, New Jersey.
As the cast of the skull was passed around in the hotel lobby at the meeting, a crowd formed. Most agreed with paleoanthropologist Fred Smith of Loyola University in Chicago when he exuded: "It's a neat little skull!"